Everything I buy has to have at least one LED, or I don't want it.
If you remember that Pink Floyd disc set that had the red flashing LED in it, I almost cried when it finally died, and the CDs' sound seemed less "live." I bought a couple of blue LED headbands and put them on my K2s. This really makes them sound cool. I think there's something about blue light that interacts with the Be and Mg drivers' output that's just magical.